Flight crew of an EMB145 inadvertently engaged the gust lock during preflight cockpit check. The gus...

Attributes
ACN	722564
Time
Date	200612
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	EMB ERJ 145 ER&LR
Operating Under FAR Part	Part 121
Flight Phase	ground : parked ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 150 flight time total : 4000 flight time type : 3000
ASRS Report	722564
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact
Consequence	other Other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft
Situations
Publication	EMB Flight Manual

Narrative:

On 12/tue/06; my crew took over an aircraft with a deferred electro-mechanical gust lock. While getting the aircraft ready for flight and boarding passenger; I inadvertently engaged the gust lock after completing the sps test; as this is a normal procedure during non-MEL operations. The gust lock engaged halfway and would not disengage regardless of what I tried to do. Maintenance was contacted and it took them nearly 2 hours to disengage the gust lock. Furthermore; on taxi-in during a later flight with the same aircraft; the first officer of the flight inadvertently engaged the gust lock again and caused another flight delay. Note: the flight controls were unaffected (free and correct) by this gust lock engagement. The only impact was to the throttle quadrant when the horizontal bar was blocking full tl movement. I am also aware of two instances during flight in which the gust lock was inadvertently (hands slipped; fidgeting during a long flight; etc) engaged halfway and could not be undone. During one instance; a landing was conducted at reduced power. Recommendations: the electro-mechanical gust lock is more dangerous than its manual cousin. It is my recommendation that when it is deferred; either the horizontal bar connecting the two actuators be removed or the actual locking mechanism be deactivated. Furthermore; there needs to be a way; while in-flight; to completely deactivate the gust lock to prevent future emergencies from happening. Callback conversation with reporter revealed the following information: the reporter stated the following: prior to departure in going through the cockpit check on the stall warning system; the gust lock lever was inadvertently bumped and activated; blocking the thrust levers at idle. The flight controls were unaffected and were free but the thrust levers were blocked and could not be unlocked. Reporter stated this system needs to be revised to allow complete deactivation in-flight.

Original NASA ASRS Text

Title: FLT CREW OF AN EMB145 INADVERTENTLY ENGAGED THE GUST LOCK DURING PREFLT COCKPIT CHECK. THE GUST LOCK HAD BEEN DEFERRED AS INOP PER THE MEL. THE GUST LOCK ENGAGED HALFWAY AND BLOCKED THE THROTTLES AT IDLE. FLT CTLS WERE UNAFFECTED.

Narrative: ON 12/TUE/06; MY CREW TOOK OVER AN ACFT WITH A DEFERRED ELECTRO-MECHANICAL GUST LOCK. WHILE GETTING THE ACFT READY FOR FLT AND BOARDING PAX; I INADVERTENTLY ENGAGED THE GUST LOCK AFTER COMPLETING THE SPS TEST; AS THIS IS A NORMAL PROC DURING NON-MEL OPS. THE GUST LOCK ENGAGED HALFWAY AND WOULD NOT DISENGAGE REGARDLESS OF WHAT I TRIED TO DO. MAINT WAS CONTACTED AND IT TOOK THEM NEARLY 2 HOURS TO DISENGAGE THE GUST LOCK. FURTHERMORE; ON TAXI-IN DURING A LATER FLT WITH THE SAME ACFT; THE FO OF THE FLT INADVERTENTLY ENGAGED THE GUST LOCK AGAIN AND CAUSED ANOTHER FLT DELAY. NOTE: THE FLT CTLS WERE UNAFFECTED (FREE AND CORRECT) BY THIS GUST LOCK ENGAGEMENT. THE ONLY IMPACT WAS TO THE THROTTLE QUADRANT WHEN THE HORIZONTAL BAR WAS BLOCKING FULL TL MOVEMENT. I AM ALSO AWARE OF TWO INSTANCES DURING FLT IN WHICH THE GUST LOCK WAS INADVERTENTLY (HANDS SLIPPED; FIDGETING DURING A LONG FLT; ETC) ENGAGED HALFWAY AND COULD NOT BE UNDONE. DURING ONE INSTANCE; A LNDG WAS CONDUCTED AT REDUCED PWR. RECOMMENDATIONS: THE ELECTRO-MECHANICAL GUST LOCK IS MORE DANGEROUS THAN ITS MANUAL COUSIN. IT IS MY RECOMMENDATION THAT WHEN IT IS DEFERRED; EITHER THE HORIZONTAL BAR CONNECTING THE TWO ACTUATORS BE REMOVED OR THE ACTUAL LOCKING MECHANISM BE DEACTIVATED. FURTHERMORE; THERE NEEDS TO BE A WAY; WHILE INFLT; TO COMPLETELY DEACTIVATE THE GUST LOCK TO PREVENT FUTURE EMERGENCIES FROM HAPPENING. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE FOLLOWING: PRIOR TO DEP IN GOING THROUGH THE COCKPIT CHK ON THE STALL WARNING SYSTEM; THE GUST LOCK LEVER WAS INADVERTENTLY BUMPED AND ACTIVATED; BLOCKING THE THRUST LEVERS AT IDLE. THE FLT CTLS WERE UNAFFECTED AND WERE FREE BUT THE THRUST LEVERS WERE BLOCKED AND COULD NOT BE UNLOCKED. RPTR STATED THIS SYSTEM NEEDS TO BE REVISED TO ALLOW COMPLETE DEACTIVATION INFLT.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Flight crew of an EMB145 inadvertently engaged the gust lock during preflight cockpit check. The gust lock had been deferred as inoperative per the MEL. The gust lock engaged halfway and blocked the throttles at idle. Flight controls were unaffected.